Mobile devices, such as notebook computers, cell phones, mobile Internet devices and portable media players are usually powered by batteries. Mobile devices can also receive power from a connection to an electrical outlet made using an alternating current (AC) adapter. The AC adapter can adjust the voltage output from the electrical outlet to a voltage appropriate for the mobile device. This AC adapter connection can also simultaneously charge the battery while providing full power for the mobile system to operate.
Mobile devices are sometimes configured to charge the batteries using the power received from the AC adapter connection, and charge the battery, often while the mobile device is operating. These mobile devices and the corresponding AC adapters are designed to provide a maximum current to charge the battery while fully powering the mobile device. Some mobile devices are configured to use a non-standard AC adapter, and these mobile devices monitor the power of the non-standard AC adapter and adjust the non-standard AC adapter power. However, using a non-standard AC adapter can be a more expensive approach. In some cases, a standard smaller size AC adapter can be used with the mobile device, but the battery can only be charged when the mobile device is off, which may greatly increase charging time and inconvenience.